1. Field of the Invention
The present invention is directed to rotary cutting tools. More particularly, the present invention concerns removal and replacement of the cutting elements or inserts used for rotary cutting tools.
2. Description of the Prior Art
Rotary cutting tools are characterized by the use of round cutting inserts which take the shape of a flat washer and which serve as the cutting surfaces of the rotary cutting tool. A representative example of such rotary cutting tools is disclosed in U.S. Pat. Re. No. 26,637.
Characteristically, the cutting inserts are mounted on a base portion of a rotary cutting tool to rotate about their own central longitudinal axis when operationally placed in contact with a workpiece. The rotation of the inserts is caused by friction between the cutting inserts and the workpiece and is continuous for as long as the cutting tool and the workpiece are in contact with each other. The speed of rotation of the insert is controllable by adjusting the radial rake of the cutting inserts.
In general, increasing the radial rake of a cutting insert will serve to increase the speed of rotation of the cutting insert and increase the dissipation of heat attendant to operation of a rotary cutting tool. Higher speeds are usually involved when the rotary cutting tool is used with harder materials, whether milling, cathing or boring is being done.
Prior art rotary cutting tools have involved the cutting inserts being mounted on the cutting surface of the tool by the use of a bolt or the like extending through the center of the insert and into a protruding base portion of the rotary cutting tool. Rotation of each cutting insert about its longitudinal axis has been accommodated by the use of a variety of bearings and bushings which are mounted with the cutting inserts on the supporting portion of the rotary cutting tool.
In the past, replacement of damaged or dulled cutting inserts would involve a major disassembly of a rotary cutting tool. Such disassembly procedure is time consuming, inconvenient, generally costly, and can involve a substantial waste of maching operating time. Having duplicate tools is not desireable from the standpoint of cost.